(1) Field of the Invention
This invention relates to filtering particles from air and cleaning the filter screen with a fluid blast.
(2) Description of the Prior Art
In the manufacture of mineral fibers, commonly known as rock wool, the manufactured fibers are carried in an air stream, the air sometimes being about 100% relative humidity. After the fibers are separated from the air, the air will still retain about 1 lb. of fibers for every 10.sup.7 cu. ft. of air. It is desirable to remove these fibers from the air before the air is discharged.
In the rock wool manufacture process in common use today the air is separated from the fibers. It is necessary that there be no appreciable back pressure applied to the air-fiber separation machines. Therefore, the pressure drop across the filter screen should be less than 1.5 inches water pressure (3.8 cm water).
Previous workers in the field have attempted to filter the fibers from the air stream using a rotating drum filter and doffing the fibers from the filter screen by brushes. The fibers as carried in the air stream will be sticky or adhesive and they tend to adhere to the screen and doffing brushes.
In filtering the air for textile plants, revolving drum air filters are used. In some instances, these air drums have a suction nozzle extending substantially the full length of the drum for removing the textile fibers from the air filter. Normally, these drums rotate in the same direction as the air which often enters the housing tangentially of the drum.
Before this application was filed, a search was made in the United States Patent and Trademark Office. The following patents were discovered on this search:
U.S. Pat. No. 350,286, Bigler PA1 U.S. Pat. No. 2,474,478, Hart PA1 U.S. Pat. No. 2,689,020, Hersey PA1 U.S. Pat. No. 2,875,846, Yonkers PA1 U.S. Pat. No. 3,339,347, Otto PA1 U.S. Pat. No. 3,345,805, Sherrill PA1 U.S. Pat. No. 4,045,194, Ferri
SHERRILL discloses a filter for filtering the air in textile plants. A suction nozzle is positioned adjacent to the filter. The suction nozzle extends for about 1/4 the length of the drum. The nozzle is moved in steps to five overlapping positions across the drum length.
BIGLER discloses a dust collector for rotating drum filters. His drum rotates opposite the direction of the tangentially entering air. The dust is removed from the filter by a knocker.
FERRI discloses an air filter for fibers and dust and the flow is from the inside of the drum to the outside of the drum. A pair of suction nozzles, which together extend for what appears to be less 1/4 the total length of the drum are opposed by air blast nozzles. The air blast nozzles and suction nozzles are mounted upon common structure which is moved back and forth along the length of the drum so that a portion of the drum is cleaned of the dust and fibers by the suction on the suction nozzle and the air blast on the air nozzles. As understood, the air blast and suction operates at all times over that strip or segment of the drum about which they are located. The drum is supported and rotated by circumferential rollers.
The remaining patents do not appear to applicant to be as pertinent as those specifically discussed above.